The inventive concept relates to an apparatus for generating a random number, and more particularly, to an apparatus for generating a random number by which a metastability signal is generated using logic gates.
Metastability is widely used in a true random number generator (TRNG) since it is known to have good stochastic properties. Conventionally, to use metastability, a latch or a flip-flop has been mainly used. However, due to various factors such as mismatch between transistors, ionizing radiation, or parasitic fluctuation of output voltages, the probability that a physical flip-flop circuit will stay in a metastable region is very low. The natural metastability rarely occurs and thus it is inefficient to use the metastable phenomenon of the flip-flop circuit. That is, the natural occurrence of metastability is very rare, thus causing a reduction in the value of either accumulated entropy or TRNG throughput.